The invention relates to a valve comprising valve housing, which contains a spool receiving means, which has lateral ports each consisting of an inlet and an outlet opening for a fluid power medium, more particularly a pneumatic one, and in which a valve spool is arranged so that it may be reciprocated between at least two switching positions and with the agency of at least one control recess is able to change a fluid power connection between individual inlet and outlet openings.
Such valves, which are also referred to as spool valves, have so far only been manufactured in two basic designs. In this respect it is a question on the one hand of round spool valves with a substantially cylindrical spool or, respectively, piston and on the other hand of flat spool valves with a flat or plate-like spool. A point in common to the two designs is the presence of control recesses cut into the surface of the spool, which in the correct position of switching render possible the flow of the fluid. However the design with the round spool has a comparatively poor hydrodynamic performance, while in the case of flat spool valves the orifices or flow cross sections are comparatively restricted. This latter disadvantage is more particularly due to the standard specifications as regards the placing of the valve fastening means.